1. Field of the Invention
The present invention relates to a joint assembly for connecting two rotatable shafts coaxially to each other, and more particularly to a joint assembly for coupling a driver shaft of a rotative drive source to a driven shaft of a driven member such as a roll for conveying a glass sheet or the like.
2. Description of the Relevant Art
Generally, glass sheets are fed through a heating furnace by feed rolls. The feed rolls are rotated about their own axes by rotative power transmitted from a rotative drive source such as a motor a driven shaft of one of the feed rolls. The driver shaft of the rotative drive source is coupled to the driven shaft of the feed roll by a joint assembly.
FIGS. 6 and 7 are conventional joint assemblies used to connect driver and driven shafts coaxially to each other.
The joint assembly of FIG. 6 comprises a sleeve 101 fixed to an end of a driver shaft 100 by a key (not shown) and a setscrew 102, a pin 105 mounted radially on a driven shaft 104 of a feed roll 103, a sleeve 106 mounted on the driven shaft 104 and engaging the pin 105 on a side thereof facing away from the driver shaft 100, a cap 109 fitted over the sleeve 106 and disposed on a side thereof facing the feed roll 103 with a retaining ring 108 interposed between the cap nut 109 and the sleeve 106, and a coil spring 107 coupling and disposed sleeves 101, 106.
The joint assembly illustrated in FIG. 7 comprises a sleeve 101' fixed to an end of a driver shaft 100 by a key (not shown) and a setscrew 102', a pin 105 mounted radially on a driven shaft 104 of a feed roll 103, a sleeve 106' mounted on the driven shaft 104 and engaging the pin 105 on a side thereof facing away from the driver shaft 100, a cap nut 109' fitted over the sleeve 106' and disposed on a side thereof facing the feed roll 103, and a leaf spring 107' coupling disposed between the sleeves 101', 106'.
A glass sheet G can be fed along by either of the feed rolls 103 shown in FIGS. 6 and 7. With the joint assemblies of FIGS. 6 and 7, there is a slight gap or backlash between the pin 105 and the sleeve 106 or 106' engaging the pin 105. Therefore, when the feed speed is varied or the glass sheet G is moved reciprocally back and forth, a play or backlash is developed between the pin 105 and the sleeve 106 or 106', causing a roll mark or scratch to be produced on the surface of the glass sheet G. The pin 105 and the sleeve 106 or 106' are held in engagement with each other by the cap 109 or the cap nut 109'. However, the cap 109 or the cap nut 109' cannot reliably be fixed to the driven shaft 104, or can easily be loosened thereon. To interconnect the shafts 100, 104 with these joint assemblies. It is necessary to use a certain types of tools, and a considerable period of time is required to install the cap 109 or 109'.